Apparatus for indicating the depth of liquids



May 15, 1928.

L. MURPHY APPARATUS FOR INDICATING THE DEPTH 0F LIQUIDS Fild July 6, 1923 Patented May 15, 1928. v

LEONARDIMURPHY, or DUBLIN, iREiiAlSl'D.

HE -rA'r APPARATUS FOR innroertive THE DEPTHOF LIQUIDS. I

Application filea nuy'e, isas sen al No 649,885,1and in-Grat Britain Octob er 19,1922. v

The invention relates to apparatus of the kind'describe'd, for example, in my U. S. Patent No. 1,294,939, for indicating the depth of liquid in a vessel,'. reservoir, river or the like. In this known apparatus air or other gas is forced to escape through the open end'of a pipe extending to thelowest' level of the liquid, the pressure exerted on the gaseous medium being measured by a barometric column of V mercury or other liquid or by a pressure gauge of for example, 3

invention is designed-to obviate these andother drawbacks;

In my British Patent-No. 2,211 of 1900 I have described a depth indicator in which a mercury seal was placed in a vessel enclosed in a closed bulb surrounding the air pipe near itslower end, but acco-rdingto the present invention the sealing liquid,such as mercury, is contained in a vessel open to the liquid and placed at the bottom of-the tank containing the liquid of which-the depth is r required. q

The sealing liquid also rises inthe tube it steam pressure is applied to the tank and prevents oil or other liquid from entering the tube. The invention will be described with reference to the accompanying drawing, in which:- J j i Fig.=1 is a vertical sectional view of on embodiment of the invention,= i

Fig. 1 is a-view 'sir'nilarto Fig. 1 of a modified form of the embodiment of the in vention shown in Fig. Land Figs. 2, 3 and 4 are views similar to Fig, 1 of other embodiments of the invention.

f In the embodiment of the invention-shown in Fig. 1011 the bottom of the tank A is placed an open cup B containinga suitable sealing liquid, such as mercury, and filled originally to-a level C. In this cup the lower open end of a tube D terminates beneath the surface of the sealing liquid.- A suitable means for forcing air through the'tube D and a pressure gauge or the like are attached to the other end of said tube. In the present 7 instance, the tubeD'is connected to the upper portion'of' a closed chamber 1? contain. I q

mg a sealing medium, such as mercury, and a tube N 15 shown as alsoextending through thetop of the chamberP. ,The tube N 'eX-- It tends through the bottom of a tube M which int-a2? A contains a suitable sealing liquid, such as.

mercury, and has its-upper end terminating near the upper end of the tube M, A tube L having its upper endclosed audits lower end immersed in the sealing liquid in the tube M, when lowered in the tube M, generates'alr pressure in the chamber P and in the tube D. A tube'O extends laterally and upwardly from the lower portion of the;

chamber P and has its upper end open to the atmosphere. When the tube L is lowered in the tube M airis forced tl'irough the tube N,

the chamber P an'dthe-tube D and thence throu'g'h'the sealing liquid in the cup 13'." The sealing liquid in the chamber P is-thus caused to rise slightly in. the tube 0 and show the'pressure due to the level'ot' the mercury in the cupthis point is now'marked as the zero or empty mark of the tank, neglecting of the cup, though this may be provided for by recessing the bottom of the tank as shown at E in Fig.1 and placing the cup in this recess with the lip of the cup "level with the bottom of the-tank. I

Liquid is now poured into thetank and as it rises enters the 'cup'and forces the sealing liquid to rise in the tube D, the sealing liquid ured. I through the fine tube D bubbles freely through the sealing liquid and 1 escapes thro'ugh-the liquid in the tank causing the indicating columnor pressure gauge to rise and show --the exact depth or pressure of liquid in the tank in excess ofthe depth of sealing liquid in" the sealing cup I It will also be obvious that pili ering the liquid inthe tank A by suction through-the pipe D is'impossible, even if a perfect vac' uumwere obtained by suction, provided the length o fthe pipe exceeds by Slinobesthe height of thehigh'est point reached by the the smalldepth of liquid ast'ar asthe lip absolutely preventing the entryinto the tubev of any of the liquid which is being nieas On the other'hand, the air jblo'wn sealing liquid in the pipe when the tanki is full.

' The "arrangement has the advantage of preventing the formation of ice in the pipe '1), asnoliquid other'than the sealing liquid can enter it.

, rise in'th st-ube under the pressureexerted k I v tending nto S flld vessel and 0f Wh eh,.th e

very deep tank.

F open at both ends rests almost on the'bo't' tom of the cup B and its appe i e'nd is above the highest point reached byv the liquid in the tank A. The pipeDi's introbliieed with in the tube li and its open end is arranged to bejust below the level ofthesealingliqmd in the cup when the tank empty. ,1 L,

This arrangement has the advantage pi not "allovvingsany Lairto fbloiv or bubble through: he liquid in the tank, I as the lse'al quid w"v se. t e l 111 h f'Pi-Pe F the height of the liquid in the taiile'lncreases,

I no liquid froin .the'tanli can enter the Ffflhe, air blown througlrthe pipellbubbles through the sealing liquid 111' pipe F nd epes i ehf i e Q1 ..1 1;f1 a latter pipe Without passing through the liquid the tank;- the i'ise of p w I liquid in the pipeF vvill' be proportional to erable distance from thetankl the heightand specific gravity of-jthe l quid I in ,the tank and the pressure" indicated by the gaugeill be the dilfereiice "betvveen the level 0t the 'sealing liquid in pipe F and in the open end, of the 'pipeD The smaller the bore ofpipe F "relatively to the inside diameter 'ofthe cup Bpthe higher the sealing ;liquid ;will rise iuthis pipe fora given depth of; liquid in the tank,

hence the relative diameters of the cup 1B and of the bore of the tube F Will ,regulate the height to which the sealing liquid Will comparatively short column or a low pressure gauge to show the liquid cq ptents of a The gauges can be marked "empirically by filling the .tank to, known: levels or, alternatively, the scales can be graduated from: the known dimensions of the tubes.

Fig. 3 shows a i'urthe'r embodimentfof the r 4 v "llquld in p a. receptacle, comprising afvessel invention; .ln'this "construction a U, tube G open end of the tube G the pipe D, is fixed so that its open end'is either beneath the surface of the sealing :liquid at H, or preferably' just touche's the: normal surface of the-"sealing liquid when thetankis drained of liquid, which surface willfoWing'sto the pressure of theliquidin the connecting pipe, be "slightly above the "level H and this level will, be constant for each apparatus when" .attaQhBCl; i i

tuliel G Wl'iich is connete to th'e t'ari'k and rise i'n the other l eg oi said tub'e, thus iIn- 11'1'e'rs'ing"the end of pipe I) more or less ac- '*01-'d'ifigt0"the' depth and gravity of the liquid in the tank, On blowing air through the pipe I) anefiactindieation' of the depth oli liquid in the tank will be shown on the pressure gauge.

,Therelative bores of thetwo legs of the J U tube'jGr Will regulate the rise of "sealing;- [liquid in the e en i gtr theftube; 'foiij the .u ,,r t fies."meeti e Yitl -i' s tei'fll il ii? a iq d i-th wr. .13. l o e l th sa rea h w Al F e a l eib i' t .1; of, the pipF consequently, though sealing asired, a loiv' p essu gauges shorter column 1 indicating apparatus to be usedlwi'th ac v .ii n Flgq 4 shows an alternat vef cons olthe U tube shown' i'n Fig. Int

su-u tion one leg'o'i' 'he t'ube' isT'placed ii ith a branch pipe K to. a discharge 'pipe J Having th saidinvention and the-b est means I kngiiviofll;

andmaymOHSequentIy be placed at 'a coii'si d' s descr bed the nature of the i the other and the tube is sholwvn eonii ec tecl',

,open at its upper end andincommunica gi i tion With the interior of said receptacleneai" la e ba e of la e th s ams l q i ained a YQ I be n vr z p sl ta, pre ure t e qu u in t e seq ftae a, a tu e through wh ch a1r ,may-, be blown 'exe,

the

lower end isim nersed in and sealed by the sealing liquid contained; in ,saidjvessel means associated jvvitli sai d tube ffor 'indi eating air pressure-therein, and a second:

n pe o t e me pher' ii-at ts; p??? ing'liquid in said vessel. 2. A device for indieating the depth oi' a ios ceptacle, the sealing liquid eontained in said s l being ex sed. to. the in' w Qt t e "liquid in the receptacle -a tube, through,"

Whieh'air may be blo'ivnl-and fof Whichthe' jlower end'is mmersed in-and'fs'ealed byjsai'di seal ng g'llquid, means associated with said tube indicating air pressuretherein, and

a second tube, opentqtheatmosphere at its 1,

upperend, surrounding the"first mentioned, v V

sealing liquidin said vessel.

Vheii the tanli is filledivith liquid; the "name to this "spebificati:on,'

sealing liquid Will fall in the leg of the LEONAR-fi tube and havingi'ts loi'ver'end sealed liify the" In testimony whereof I have Signed 

